Unlike with CLI, here a new answers file (INI based) will be created.
This file contains all the default & mandatory parameters in a section of its own (named virsh in our case), so the user can easily replace all mandatory parameters.
When the file is ready, it should be provided as an input for the --from-file option.

[virsh]host-key=Required argument. Edit with any value, OR override with CLI: --host-key=<option>host-address=Required argument. Edit with any value, OR override with CLI: --host-address=<option>topology-nodes=Required argument. Edit with one of the allowed values OR override with CLI: --topology-nodes=<option>host-user=root

Note

host-key, host-address and topology-nodes don’t have default values. All arguments can be edited in file or overridden directly from CLI.

Note

Do not use double quotes or apostrophes for the string values
in the answers file. Infrared will NOT remove those quotation marks
that surround the values.

Just like in the provisioning stage, here also the user should take care of the mandatory parameters
(by CLI or INI file) in order to be able to start the installation process.
Let’s deploy a TripleO Undercloud:

infraredtripleo-undercloud--version10--images-taskrpm

This will deploy OSP 10 (Newton) on the node undercloud-0 provisioned previously.